Three Sunday homicides mean May is 3rd-deadliest month in 40 years in Baltimore.

With three men killed in eastside shootings on Sunday, Baltimore recorded its deadliest month in more than 40 years.

The 43 killings in May surpassed the 42 homicides the city saw in August 1990, and left Mayor Stephanie Rawlings-Blake defending police and her administration.

Speaking at a morning ceremony to honor McKenzie Elliott, the 3-year-old killed by a stray bullet in August, Rawlings-Blake said it's time to stop finger-pointing and assigning blame for the recent violence.

The killing of African-Americans in Baltimore has to stop, she said, noting that 189 of the 208 killed last year were black men. For the city to improve, all homicides need to drop, she added.

"We have to do better," the mayor said. "We have to want more."

City Councilman Brandon Scott, vice chair of the public safety committee, echoed that theme, saying it's time for all Baltimoreans to have honest conversations about ways to stop the violence.

There isn't one solution or one person who shoulders the blame, he said, adding that homicides affect all residents in the city, not just those in the poorest neighborhoods.

"Too many people have died in our town," he said Sunday afternoon. "Don't point fingers or go to social media. Everybody has to look in the mirror and ask, 'What are they doing?'"

The city's 43rd homicide in May occurred late Sunday morning, when two men were shot in the back in the 1900 block of Collington Ave. in the South Clifton Park section of East Baltimore. One victim was pronounced dead at the scene at 11:37 a.m., according to police, while the second victim walked into an area hospital. His condition was not immediately available.

The 41st and 42nd homicides took place hours earlier, when two men were fatally shot in the head, police said. The double homicide occurred around 1:15 a.m. in the 2000 block of Belair Road in the Clifton Park section of East Baltimore, police said.

Police did not identify the victims, a suspect or a motive in either shooting. The department's homicide detectives are investigating both shootings, and anyone with information may call 410-396-2100.

Sunday's homicides — which brought the total for 2015 to 116 — came amid a continuing spike in shootings.

Hours before and just a block away from the double shooting on Collington Avenue, police found a man suffering from gunshot wounds in the 2000 block of N. Washington St. The man was transported to an area hospital with non-life-threatening injuries.

Police did not immediately say if the South Clifton Park shootings were related.

Police leaders and the mayor have not pinpointed a reason for the increase, and a spokeswoman for the Baltimore Police Department declined to comment on Sunday.

Baltimore has recorded more homicides in a single month: There were 44 in December 1971 and 45 in August 1972.

But in that era, the city had approximately 908,000 residents — nearly 300,000 more than today.

Peter Moskos, a former Baltimore police officer who is an assistant professor at the John Jay College of Criminal Justice in New York, called May the city's deadliest month ever based on the per-capita homicide rate.

Baltimore's homicide rate per 100,000 population in May was 6.1 — topping the rates in the early 1970s, Moskos wrote Friday on his "Cop in the Hood" blog.

"Put another way, even if no other people had been murdered in Baltimore before May, and even if no more people were killed from today until 2016, Baltimore would still have an above average annual homicide rate just based on the May killings," Moskos wrote.

Baltimore isn't alone when it comes to a homicide increase.

As of Sunday, St. Louis recorded 70 homicides for the year, 18 ahead of the same period in 2014, according to the St. Louis Post-Dispatch.

Some Baltimore officials have speculated that the spike in violence can be partly attributed to the looting of drugs from pharmacies during riots that followed the death of Freddie Gray.

During April's riots, thousands of dollars in narcotics and other drugs were stolen from more than 20 Baltimore pharmacies. Twenty-seven pharmacies reported damage during the unrest.

The U.S. Drug Enforcement Administration and police are investigating the thefts, but neither knows how many opiates were taken. Investigators have yet to interview all the business owners.